Sectional boiler



P H. A. FISCHEL.

SECTIONAL BOILER Filed 001;. 18, 19 55 2 Sheets-Sheet '1 Sept. 10, 1935.HEL 2,014,171

SECTIONAL BOILER Filed Oct. 18, 1933 2 Sheets-Sheet 2 FIG. 1o

Patented Sept. 10, 1935 UNITED STATES SECTIONAL BOILER Hermann AlbertFischel, Berlin-Lichtcrfelde st, Germany Application October 18, 1933,Serial No. 694,157 In Germany October 21, 1932 3 Claims.

This invention relates to a sectional boiler for water or low pressuresteam and has for its object to make it possible to burn low qualityfuel as well, for instance, crude lignite in a more perfect manner thanhitherto, even without expert attention.

The peculiarity of the boiler consists, in the first place,substantially in this that the fire bridge divides up the fire space andextends into it for a considerable distance, the complete combustion ofthe fire gases taking place with a free development of the flames abovethe fire bridge in the roomy recombustion chamber. The fire bridge hasthe advantage that its under side acts as an ignition arch for thegaseous products of incomplete combustion and for fuels which do notreadily ignite, while its upper surface, which acts as a radiatingsurface, favours the combustion in the recombustion chamber lying abovethe fire space and the constriction at its end produces eddies whichcause the flue gases to mix with the additional air. In order that theradiating effect of the upper surface of the fire bridge shall not behindered by particles of flue dust settling on it, this surface ispreferably placed at such a steep angle that the flue dust is forced toslide down.

A constructional form of the boiler is shown in Figures 1 to 8 of theaccompanying drawings.

Figure 1 is a vertical cross section through this constructional form ofboiler. The fire plate which is in one piece, is provided at its lowerend with slots 8 for the passage of the primary air. The plate rests oneither side on supports 1" provided on the inside of the boiler walls.

Figure 2 is a horizontal cross section through the boiler on the sectionline ab Figure 1.

Figures 3, 4 and 5 show different possible constructions of the fireplate. It will be seen that the plate may consist of separate blocks pwhich placed next to one another form the cover in the front part of thefire space and are provided in the rear part opposite the air inlet withthe slotlike openings s.

Figures 6 and '7 show in plan view and elevation a constructional form,in which a plurality of prism-like elongated blocks p rests on thesupports 1*, covering blocks p1 resting in the front part of the bridgeon the elongated blocks and leaving the fire slots in the rear part ofthe bridge open.

Figure 8 shows an arrangement in which the fire plate does not occupythe whole breadth of the fire space and the supports or projections ofthe boiler sections project sufficiently far from the inlet side of theadditional air to support the outer portion of the fire plate.

A further constructional form of the sectional boiler is shown inFigures 9 to 11. The main feature of this form of construction is theintroduction of the fuel between the boiler sections which form a closedframe around the furnace. This constitutes a considerable simplificationand improvement of the constructional forms hitherto used.

Figure 9 is a vertical cross-section through the boiler, and Fig. 10 isa horizontal section through the furnace, showing the trapezium-likeshape of the boiler sections at the side where the fuel is introducedand the arrangement of the grates. Figure 11 is a cross-section throughthe parts of the sections supporting the grate r.

From the hopper F the fuel passes laterally between the separatesections G of the boiler into the furnace. Between the relatively narrowwater-carrying sections G sufficient space is provided. Preferably thesections have a cross-section which tapers from the hopper to thefurnace (Fig. 10).

In order to ensure a suflicient supply of air when there is aconsiderable depth of fuel on the fire, grate plates P are providedbetween the sections G, the inclination of which plates is greater thanthe sliding angle of the fuel, so that the accumulation of fine ashwhich would occur with horizontal or less inclined plates is preventedand the supply of combustion air is not hindered.

Below the grate plates is the grate proper R, which is formed on the onehand by the lower parts of the boiler sections and on the other hand bygrate bodies 1 which are interposed or are cast on the sections. Theformer grate bodies are made easily movable in order that by shakingthem the ash may be removed or by withdrawing them further clinker andash may be deposited in the ash chamber. They may be shaken eitherseparately by hand after the fire door has been opened, or jointly bymeans of a cam shaft or the like from the outside without opening thefire door. The shape of the grate bodies is made suitable for theproperties of the fuel used.

What I claim is:

1. In a sectional boiler a boiler body having a fire space therein, afuel hopper disposed laterally of the boiler body and communicating withthe fire space, said body including a plurality of separatewater-containing sections having spaces between the sections for theintroduction of the fuel from the said hopper into the fire space, afire bridge extending into the fire space of the boiler at a point abovethe point of communication of the hopper with the fire space andextending for a considerable distance and dividing it up into a lowerspace and a capacious upper recombustion chamber for the fire gases, inwhich complete combustion with a free flame development can take place,and means for the intro- 10 duction of preheated additional air into thefire space of the boiler opposite the said fire bridge.

2. A sectional boiler as claimed in claim 1, wherein the boiler sectionshave a trapeziform cross-section where the fuel is introduced taperingfrom the hopper to the fire space.

3. A sectional boiler as claimed in claim 1, wherein a grate is disposedbetween the separate water container boiler sections and rests on saidsections.

HERMANN ALBERT FISCHEL.

